Why are parts of Italian Alps pink? It could be due to ice-melting algae and that's not good, say scientists
An alga has taken over parts of a glacier in the Italian Alps, turning them pink. Though considered a treat to the eyes, they are known to induce ice melting. Scientists are trying to study how they came to colonize the region and also understand their connection with climate change.
The alga was probably Chlamydomonas nivalis (a snow alga), not Ancylonema nordenskioeldi (a glacier alga), Biagio Di Mauro, a researcher at the Institute of Polar Sciences, tweeted. Reports had suggested that the latter, which is commonly found in Greenland, was behind the pink appearance. Typically, the snow algae colonize the snowfields of the alps and polar regions all over the world. The phenomenon is quite common in the Alps, he added.
"The alga is not dangerous, it is a natural phenomenon that occurs during the spring and summer periods in the middle latitudes but also at the Poles," Di Mauro, who had previously studied the algae at the Morteratsch glacier in Switzerland, reportedly said. "Glaciers and ice sheets are not lifeless," Di Mauro and his colleagues wrote in a study. Several species of microorganisms, algae and small arthropods grow on melting ice and snow.
Several factors fuel climate change, but the contribution from algal sources is not clear. Because ice is white, it reflects most sunlight into space. But the algal growth turns the ice darker, allowing the absorption of heat. This promotes the melting of underlying snow or ice. "Everything that darkens the snow causes it to melt because it accelerates the absorption of radiation," said Di Mauro.
Scientists are also interested in studying how algal growth affects the climate crisis. "We are trying to quantify the effect of other phenomena besides the human one on the overheating of the Earth," Di Mauro explained. He, however, added that the relationship with climate change is yet to be proven. Di Mauro suspects that hikers and ski lifts might impact the algae. Tourists are reportedly unhappy about the change. "Overheating of the planet is a problem. The last thing we needed was algae," said tourist Marta Durante. "Unfortunately, we are doing irreversible damage. We are already at the point of no return, I think."
Another tourist named Elisa Pongini from Florence feared that the Earth was "giving us back everything we have done to it". "2020 is a special year: terrible things have happened," she said. "In my opinion, atmospheric phenomena are worsening. Climate change is increasingly evident."
There are other concerns too. Cryoconite, which is dust carried by winds blowing from polluted sites, reaches the glaciers and settles as black holes on the surface. The dark regions then absorb more sunlight, accelerating melting. They also provide shelter to certain microbial communities. "The identification of all the players involved in ice darkening is a fundamental task for understanding surface glacier melt, and for predicting the response of Alpine glaciers to future climate change," Di Mauro and his colleagues wrote in their study.